330 一体型トンネル内煙霧透過率計の開発(S39-1 トンネルの空気力学と換気(道路と環境),S39 トンネルの空気力学と換気)  [in Japanese] 330 Development of Integrated-type Visibility Meter for Road Tunnels  [in Japanese]

The existing visibility meter has a measuring distance of 100m, and has the problem that the absolute value of visibility is not correctly calibrated because the light source and detector are away. This paper is on the development of the new visibility meter that has the multi-path reflection with the astigmatism mirror on both sides. Further more the light source (laser diode) and the optical detector are integrated, while the measuring distance is maintained. The visibility meter made for trial purposes was set up in an actual tunnel, and the comparison experiment with the existing visibility meter is done. As a result, it can obtain temporal resolution almost with the existing.